Reel-to-reel substrate tape polishing system

ABSTRACT

Disclosed is a reel-to-reel single-pass mechanical polishing system ( 100 ) suitable for polishing long lengths of metal substrate tape ( 124 ) used in the manufacture of high-temperature superconductor (HTS) coated tape, including multiple instantiations of a polishing station ( 114 ) in combination with a subsequent rinsing station ( 116 ) arranged along the axis of the metal substrate tape ( 124 ) that is translating between a payout spool ( 110   a ) and a take-up spool ( 110   b ). The metal substrate tape obtains a surface smoothness that is suitable for the subsequent deposition of a buffer layer.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from provisional applicationU.S. S No. 60/273,195 filed Mar. 2, 2001.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was conceived while working under a governmentcontract with the New York State Energy Research and Development Agencyunder reference 4466L-IABR-IA99.

FIELD OF THE INVENTION

[0003] The present invention relates to the field of mechanicalpolishing. More particularly, the present invention relates to a systemfor mechanical polishing of long lengths of translating metal substratetape used in the manufacture of high-temperature superconductor (HTS)tape.

BACKGROUND OF THE INVENTION

[0004] Wire forms the basic building block of the world's electric powersystem, including transformers, transmission and distribution systems,and motors. The discovery of revolutionary HTS compounds in 1986 led tothe development of a radically new type of wire for the power industry;this discovery is the most fundamental advance in wire technology inmore than a century. However, to date only short samples of theHTS-coated tape used in the manufacture of next-generation HTS wireshave been fabricated at high performance levels. In order for HTStechnology to become commercially viable for use in the power generationand distribution industry, it will be necessary to develop techniquesfor continuous, high-throughput production of HTS-coated tape.

[0005] A typical HTS tape is a 3-layer laminate of a support layer, abuffer layer and a HTS film. The support layer is typically composed ofstainless steel or nickel and provides structural integrity andflexibility to the tape. The buffer layer buffer layer is disposedbetween the metal substrate and the HTS film to prevent reaction betweenthe substrate and the HTS film and, importantly, acts as a template forepitaxial growth of the HTS film. Typical buffers are yttrium-stabilizedzirconia (YSZ) or cerium oxide (CeO₂). The HTS film is formed of, forexample, yttrium-barium-copper-oxide (YBCO).

[0006] Presently, substrates are polished by well-known mechanical,chemical, or electrical means to achieve a high degree of planarity orsurface smoothness. Planarity is important in the manufacture ofintegrated circuits and numerous processes have been developed to meetthe requirement of achieving a high degree of surface smoothness in thesilicon wafer substrates used in manufacturing such electroniccomponents.

[0007] One type of polishing process, mechanical polishing, holds astationary substrate on a rotating pad and presses it against aconformable rotating polishing pad. Mechanical polishing may beperformed in conjunction with a chemically active abrasive solventslurry, a process commonly referred to a chemical mechanical polishing,which provides a higher material removal rate.

[0008] The abrasive slurry is typically comprised of small very hardparticles such as diamond or boron oxide. The size of the particles usedand other parameters, such as rotation speed, duration and contact forcedetermine the removal rate and eventual roughness of the substrate.

[0009] In order to achieve high current densities in the HTS film, oneof the main requirements is that the substrate be very smooth, withminimal surface imperfections. When the coatings are in form of thinfilms (up to 10 microns), the surface quality of the substrate becomescritical. Defects in the surface of the metal substrate can lead tovoids, delamination, undesired texture, and roughness in the coatings.Furthermore, these imperfections or roughness on the substrate surfacecan be transmitted through the intermediate buffer layer and lead to adefect in the HTS film, which in an HTS-coated tape application musthave a high degree of planarity, with minimal surface imperfections overlong lengths.

[0010] A number of surface polishing techniques are known to the art.One such polishing technique is described in Kubo, U.S. Pat. No.5,938,502, dated Aug. 17, 1999 and entitled “Polishing Method OfSubstrate And Polishing Device Therefor”. Kubo describes a methodemploying a polishing pad and a slurry. The polishing device includes abed formed with a polishing pad on the surface and driven for rotation,a rotatable carrier for holding the substrate to be polished, and aslurry supply means for supplying a slurry as an abrasive to the surfaceof the polishing pad. The substrate is polished by the abrasive slurryand the polishing pad, while pressing the substrate held by the carrieronto the polishing pad. Kubo's polishing technique may require severalpasses to achieve the smoothness required for an HTS-coated tapeapplication.

[0011] Kubo's technique however, is applicable only to stationarysubstrates and is not suitable for the polishing of long lengths ofcontinuously translating substrate tape. Furthermore, in themanufacturing of HTS-coated tape it is preferable to complete thesurface preparation of the substrate in one pass so as to increasethroughput and reduce cost. Thus, another drawback of Kubo's polishingtechnique is that it requires several passes and is therefore notsuitable to a process for polishing long lengths of continuouslytranslating substrate tape.

[0012] Shendon, U.S. Pat. No. 6,336,851, dated Jan. 8, 2002 and entitled“Substrate Belt Polisher,” describes a flexible membrane-polishing beltagainst which a substrate for a semiconductor wafer is polished usingchemical mechanical polishing principles. A fluidized layer is providedon a surface of a polishing member backing assembly, which urges themoving polishing membrane toward the substrate held in a polishing head.The linear motion of the belt provides uniform polishing across the fullwidth of the belt and provides the opportunity for a chemical mechanicalpolishing to take place. Several configurations are disclosed. Theyinclude belts which are wider than the substrate being polished, beltswhich cross the substrate being polished, but which provide relativemotion between the substrate and the polishing belt, and polishing beltcarriers having localized polishing areas which are smaller than thetotal area of the substrate to be polished. Only a small area on thesurface of the substrate is in contact with polishing membrane but themotion of the carrier with respect to the substrate is programmed toprovide uniform polishing of the full substrate surface, as is eachconfiguration described.

[0013] Jackson et al., U.S. Pat. No. 6,241,591, dated Jun. 5, 2001, andentitled “Apparatus And Method For Polishing A Substrate,” describes apolishing apparatus. Uniform pressure distribution allows asemiconductor substrate polished with the polishing apparatus to havereduced edge exclusion, and thus increased die yield.

[0014] Nagahara et al., U.S. Pat. No. 6,179,690, dated Jan. 30, 2001,entitled “Substrate Polishing Apparatus,” describes a chemicalmechanical polishing apparatus that includes a rotating plate on which asubstrate is received, and a polishing pad, which moves across thesubstrate as it rotates on the plate to polish the substrate. The loadof the pad against the substrate, and the rotary speed of the plate, maybe varied to control the rate of material removed by the pad.

[0015] Sarfaty et al., U.S. Pat. No. 5,741,171, dated Apr. 21, 1998 andentitled “Precision Polishing System,” describes a polishing system ableto polish samples to accuracy within the sub micron range. The polishingsystem has applications in the semiconductor field for use in polishingsilicon wafers during testing and quality control inspections.

[0016] However, none of these prior art polishing systems are capable ofsolving the problem existing during the manufacture of HTS tape, viz.how to polish a continuously moving length of material in a single pass.

[0017] It is an object of this invention to provide a polishing systemamendable to continuous production of HTS tape in a one-pass operation.

[0018] It is therefore an object of the invention to provide a systemand method for surface preparation of long lengths of metal substratesin a continuous manner.

[0019] It is another object of the invention to provide a polishingsystem and method for producing a surface roughness of the substratethat is of very high quality, suitable to achieve high current densitiesin long lengths of superconducting tapes, in a single polishing pass.

SUMMARY

[0020] The polishing system of the present invention is a reel-to-reelsingle-pass continuous mechanical polishing system suitable forpolishing long lengths of metal substrate tape used in the manufactureof HTS-coated tape. The polishing system of the present inventionincludes multiple instantiations of a surface treatment unit, eachcomprising a polishing station in combination with a subsequent rinsingstation arranged along the axis of a metal substrate tape that iscontinuously translating between a payout spool and a take-up spool. Bytranslating through the multiple instantiations of a polishing stationin combination with a subsequent rinsing station, the metal substratetape experiences a series of polishing and cleaning events toprogressively diminish its surface roughness and achieve a surfacesmoothness that is acceptable for depositing a buffer layer for use inthe manufacture of HTS-coated tape.

[0021] More specifically, disposed within each polishing station aremultiple polishing wheels upon which is dispensed a polishing medium,such as a slurry formed by mixing an abrasive material and water. Withineach polishing station one surface of the translating metal substratetape is in contact under pressure with the polishing wheels andpolishing medium. As the HTS tape translates through the polishingoperation, the surface imperfections are gradually removed by varyingthe parameters of the process, such as size and hardness of theabrasive.

[0022] The hardness of the polishing wheels disposed within thesuccessive polishing stations typically varies from very hard to hard tosoft as the relative position of the polishing stations progress alongthe line from the front end of the polishing system (the payout spool)to the back end of the polishing system (the take-up spool). Theparticle size of the polishing medium used in the successive polishingstations ranges, for example, from 1.0 to 0.3 to 0.05 microns as therelative position of the polishing stations progress along the line fromthe front end of the polishing system to the back end of the system. Inthis way, the metal substrate tape experiences, via progressive stages,rougher to finer polishing events, each in combination with a respectiverinsing event, as it translates through the polishing system, therebyachieving in a single pass through the polishing system a surfacesmoothness that is suitable for the subsequent deposition of a bufferlayer.

[0023] The translation of the metal substrate tape through the polishingsystem is accomplished via a tape feeder assembly that is driven by astepper motor for providing a controlled rate of translation to allowthe proper exposure time of the metal substrate tape to the polishingand cleaning events. The tape feeder assembly operates in combinationwith the payout spool and the take-up spool that are each driven by atorque motor for controlling the tension of the metal substrate tape asit translates through the polishing system of the present invention.

[0024] Lastly, the polishing system of the present invention includes anoptical surface roughness measurement gage at the back end of thepolishing system for monitoring the finished surface quality of themetal substrate tape.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 illustrates a high-level diagram of a polishing system ofthe present invention suitable for polishing long lengths of metalsubstrate tape used in the manufacture of HTS-coated tape.

[0026]FIGS. 2A and 2B illustrate a side view and a front view,respectively, of a spool suitable for use as the payout and take-upspool within the polishing system of the present invention.

[0027]FIGS. 3A, 3B, and 3C illustrate a side view, a top view, and anend view, respectively, of a substrate tape drive mechanism suitable foruse as the tape feeder apparatus within the polishing system of thepresent invention.

[0028]FIGS. 4A, 4B and 4C illustrate a side view, a top view, and an endview, respectively, of a mechanical polisher suitable for use as apolishing station within the polishing system of the present invention.

[0029]FIG. 5 illustrates a side view of a pressure device suitable foruse within the polishing station illustrated in FIGS. 4A, 4B and 4C.

[0030]FIGS. 6A and 6B illustrate a side view and an end view,respectively, of a substrate tape cleaning mechanism suitable for use asa rinsing station within the polishing system of the present invention.

[0031]FIG. 7 illustrates a top view of a mechanical polisher suitablefor use as the final polishing station within the polishing system ofthe present invention.

[0032]FIGS. 8A and 8B illustrate a side view and a top view,respectively, of a substrate tape cleaning mechanism suitable for use asthe final rinsing station within the polishing system of the presentinvention.

[0033]FIG. 9 is a flow diagram illustrating a method of operation of thepolishing system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0034]FIG. 1 illustrates a polishing system 100 in accordance with theinvention. The polishing system 100 of the present invention is amechanical polishing system suitable for polishing long lengths of metalsubstrate tape used in the manufacture of HTS-coated tape.

[0035] The polishing system 100 includes multiple instantiations of aspool 110 (i.e., a spool 110 a and a spool 110 b). The spool 110 aserves as a payout spool located at the entry point of the polishingsystem 100. Upon the spool 110 a is wound a length of substrate tape 124that is formed of metals, such as stainless steel or a nickel alloy suchas Inconel. The substrate tape 124 has a non-polished surface 126 and apolished surface 128. The substrate tape 124 is capable of withstandinghigh temperatures and vacuum conditions, and is typically between 3 mmand 1 cm in width and upwards of several hundred meters in length. Thesubstrate tape 124 typically has several meters of “leader” at both endsto aid in handling. The substrate tape 124 is laced through thepolishing system 100 from the spool 110 a and wound onto the spool 110 bthat serves as a take-up spool at the exit point of the polishing system100. Each spool 110 is driven by a torque motor and is described indetail in FIGS. 2A and 2B.

[0036] The polishing system 100 further includes a tape feeder 112 thatis a set of motor-driven belts that serve as the driving mechanism fortranslating the substrate tape 124 through the polishing system 100. Thetape feeder 112 also guides the substrate tape 124 from the spool 110 ainto a first instantiation of a polishing station 114. The tape feeder112 is described in detail in FIGS. 3A and 3B.

[0037] The polishing system 100 further includes multiple instantiationsof a polishing station 114, for example, a polishing station 114 a, apolishing station 114 b, and a polishing station 114 a; where eachpolishing station 114 includes a stainless steel tank containing a setof polishing wheels that contact the substrate tape 124 in combinationwith a polishing medium, such as aluminum oxide. Furthermore, eachpolishing wheel within the polishing station 114 has an associatedpressure device for applying pressure upon the substrate tape 124against the respective polishing wheel. The polishing station 114 isdescribed in detail in FIGS. 4A, 4B, and 4C. The pressure device isdescribed in detail in FIG. 5.

[0038] The polishing system 100 further includes multiple instantiationsof a rinsing station 116, for example, a rinsing station 116 a, arinsing station 116 b, and a rinsing station 116 c; where each rinsingstation 116 includes a stainless steel tank containing a sprayerassembly for applying de-ionized water or standard tap water to thesubstrate tape 124 for rinsing the polishing medium from the substratetape 124. The rinsing station 116 is described in detail in FIGS. 6A and6B.

[0039] The polishing system 100 further includes a polishing station 118that serves as a final polishing station; where the polishing station118 includes a stainless steel tank containing multiple sets ofpolishing wheels that contact the substrate tape 124 in combination witha polishing medium, such as aluminum oxide. Furthermore, each polishingwheel within the polishing station 118 has an associated pressure devicefor applying pressure upon the substrate tape 124 against the respectivepolishing wheel. The polishing station 118 is described in detail inFIG. 7.

[0040] The polishing system 100 further includes a rinsing station 120that serves as a final rinsing station; where the rinsing station 120includes a stainless steel tank containing multiple sprayer assembliesfor applying de-ionized water or standard tap water to the substratetape 124 for rinsing the polishing medium from the substrate tape 124.Furthermore, the rinsing station 120 includes a set of soft polishingwheels for removing the last remaining residue of the polishing medium.The rinsing station 120 is described in detail in FIGS. 8A and 8B.

[0041] With continuing reference to FIG. 1, all elements of thepolishing system 100 are arranged in a line along the axis of thesubstrate tape 124 formed between the spool 110 a and the spool 110 b.More specifically, the substrate tape 124 is unwound from the spool 110a and is laced through the tape feeder 112, then subsequently throughthe first polishing station 114 (i.e., polishing station 114 a), thensubsequently through the first rinsing station 116 (i.e., rinsingstation 116 a), then subsequently through the second polishing station114 (i.e., polishing station 114 b), then subsequently through thesecond rinsing station 116 (i.e., rinsing station 116 b), thensubsequently through the third polishing station 114 (i.e., polishingstation 114 c), then subsequently through the third rinsing station 116(i.e., rinsing station 116 c), then subsequently through the polishingstation 118, then lastly through the rinsing station 120 and onto thespool 110 b.

[0042] Disposed between the spool 110 a and the tape feeder 112 is aguide wheel 130. Likewise, disposed between the rinsing station 120 andthe spool 110 b is a guide wheel 132. The guide wheels 130 and 132 arein contact with the polished surface 128 of the substrate tape 124 andassist in supporting and guiding the substrate tape 124 as it translatesalong the polishing system 100. The guide wheels 130 and 132 are formedof a material that is not damaging to the polished surface 128 of thesubstrate tape 124, such materials include Teflon or soft rubber.

[0043] Lastly, and optionally, the polishing system 100 includes aroughness monitor 122 disposed between the guide wheel 132 and the spool110 b and directed at the polished surface 128 of the substrate tape124. The roughness monitor 122 is mounted on a 3-axis adjustable stage(not shown), such that its position relative to the polished surface 128of the substrate tape 124 may be adjusted. The distance between thesubstrate tape 124 and the roughness monitor 122 is set appropriatelyfor measuring roughness to the required accuracy. The roughness monitor122 provides a quality check mechanism at the exit point of thepolishing system 100. The roughness monitor 122 is an optical surfaceroughness measurement gage, such a LASER^(CHECK) device manufactured byOptical Dimensions LLC, which is designed to measure the surfaceroughness over which it passes. In the case of the polishing system 100of the present invention, the roughness monitor 122 provides an averagesurface roughness of the polished surface 128 of the substrate tape 124.

[0044]FIGS. 2A and 2B illustrate a side view and a front view,respectively, of the spool 110 that is suitable for use as the payoutspool (i.e., the spool 110 a) and take-up spool (i.e., the spool 110 b)of the polishing system 100 of the present invention. The spool 110includes a reel 210 mechanically connected to a motor 212 via arotatable shaft 214. The reel 210 is a reel upon which the substratetape 124 is wound. The diameter and width of the reel 210 may varydepending on the dimensions of the substrate tape 124. The motor 212 isa conventional torque motor, such as an Oriental Motor 5TK20GN. Wheninstalled the torque exerted by the spool 110 a is opposite the torqueexerted by the spool 110 b to provide the proper tension on thesubstrate tape 124 as it unwinds from the spool 110 a and translatesthrough the polishing system 100 and subsequently winds onto the spool110 b.

[0045]FIGS. 3A, 3B, and 3C illustrate a side view, a top view, and anend view, respectively, of the tape feeder 112. The tape feeder 112 is asubstrate tape drive mechanism suitable for use as the tape feederapparatus within the polishing system 100 of the present invention. Thetape feeder 112 provides a controlled rate of translation to allow theproper exposure time of the substrate tape 124 to the polishing andcleaning events that take place within the polishing system 100.

[0046] With reference to FIG. 3A, the tape feeder 112 includes a beltassembly 310 that further includes a belt 312 forming a loop around aconventional pulley 314 and a conventional pulley 316. Additionally, thetape feeder 112 includes a belt assembly 318 that further includes abelt 320 forming a loop around a conventional pulley 322 and aconventional pulley 324. Such that the belt assembly 310 and the beltassembly 318 are arranged in parallel with one another in a stackedfashion such that the outer surface of the belt 312 is facing the outersurface of the belt 320, as shown in FIGS. 3A and 3C.

[0047] With reference to FIGS. 3A, 3B, and 3C, the belt assembly 310 andthe belt assembly 318 are mechanically coupled via a mechanical driveassembly 326 and rotatably driven by a motor 328 that is a conventionalstepper motor, such as an Oriental M540-401-115 motor. The driveassembly 326 is designed using various belts, pulleys and gears (notshown) in a conventional manner such that in operation the belt assembly310 rotates in a direction opposite the belt assembly 318. For example,if the pulleys 314 and 316 of the belt assembly 310 are rotatingcounter-clockwise, then the pulleys 322 and 324 of the belt assembly 318are rotating clockwise.

[0048] In operation, as the substrate tape 124 is fed through the tapefeeder 112, the outer surface of the belt 312 of the belt assembly 310is in contact with the non-polished surface 126 of the substrate tape124 and the outer surface of the belt 320 of the belt assembly 318 is incontact with the polished surface 128 of the substrate tape 124, asshown in FIGS. 3A and 3C. As a result, the spacing between the beltassembly 310 and the belt assembly 318 is dependent upon the thicknessof the substrate tape 124. The pressure exerted on the substrate tape124 by the belt 312 and the belt 320 creates sufficient friction tocause the substrate tape 124 to translate through the tape feeder 112due to the rotation of the belt 312 and the belt 320.

[0049]FIGS. 4A, 4B and 4C illustrate a side view, a top view, and an endview, respectively, of the polishing station 114 that is a mechanicalpolisher suitable for use within the polishing system 100 of the presentinvention.

[0050] The polishing station 114 includes a polisher assembly 410 and aslurry dispenser 412 disposed within a tank 414 formed of stainlesssteel. The tank 414 has an entry slot 416 and an exit slot 418 throughwhich the substrate tape 124 may translate. Inserted in the entry slot416 and the exit slot 418 is a squeegee (not shown) formed, e.g. ofsilicon rubber and felt for removing excess slurry from the substratetape 124 as it passes therethrough.

[0051] The polisher assembly 410 includes a polishing wheel 420 mountedon a rotatable shaft 422 whose ends pass through opposing walls of thetank 414 leaving the polishing wheel 420 suspended within the tank 414.Similarly, the polisher assembly 410 includes a polishing wheel 424mounted on a rotatable shaft 426 whose ends pass through opposing wallsof the tank 414 leaving the polishing wheel 424 suspended within thetank 414. When installed, the polishing wheel 420 and the polishingwheel 424 of the polisher assembly 410 are aligned along the axis of thesubstrate tape 124 passing through the tank 414. Additionally, thepolishing wheel 420 and the polishing wheel 424 of the polisher assembly410 are aligned on a horizontal plane such that they make contact withthe polished surface 128 of the substrate tape 124.

[0052] The polishing wheel 420 and the polishing wheel 424 are, forexample, four inches in diameter. The polishing wheel 420 and thepolishing wheel 424 are diamond hard felt polishing wheels, such asmanufactured by Boston Felt, with a “Shore A hardness” above 85 or afunctionally equivalent material. Alternatively, the polishing wheel 420and the polishing wheel 424 are hard felt polishing wheels formed bypure felt, such as manufactured by Boston Felt, with a “Shore Ahardness” in the range of 30 to 85 depending on which polishing stationthey are operating within, i.e., the polishing station 114 a, 114 b, 114c, or 118. Shore hardness is a well-known measure of the resistance of amaterial to indentation by a spring-loaded indenter. The Shore hardnessscale is a raw number between 0 and 100 with no units, the higher thenumber, the greater the resistance, i.e. the harder the material.Materials with appropriate Shore hardness may be substituted.

[0053] A conventional motor 428 rotatably drives the shaft 422 andsubsequently the polishing wheel 420. The motor 428 additionally drivesthe shaft 426 and subsequently the polishing wheel 424 via a belt 430that couples the rotational motion of the shaft 422 to the shaft 426 viapulleys (not shown). The motor 428 is, for example, a conventional 0.5hp motor, such as a Dayton 5K984D motor, that is capable of a rotationalspeed of up to 1600 rpm. FIG. 4B illustrates but one example drivingmechanism, those skilled in the art will appreciate that the shaft 422and the shaft 426 may be rotatably driven by other conventional means.

[0054] The polisher assembly 410 further includes multipleinstantiations of a pressure assembly 432, for example a pressureassembly 432 a associated with the polishing wheel 420 and a pressureassembly 432 b associated with the polishing wheel 424. In operation,the substrate tape 124 is sandwiched between the pressure assembly 432 aand the polishing wheel 420, and between the pressure assembly 432 b andthe polishing wheel 424. As a result, the pressure assembly 432 a andthe pressure assembly 432 b apply pressure onto the non-polished surface126 of the substrate tape 124 that in turn transfers pressure to thepolished surface 128 of the substrate tape 124 against the polishingwheel 420 and the polishing wheel 424, respectively. The pressureassembly 432 is described in detail in FIG. 5.

[0055] The slurry dispenser 412 further includes an inlet 434 feeding afirst outlet 436 and a second outlet 438. The inlet 434 enters throughthe wall of the tank 414 and feeds the outlet 436 that is directedtoward the polishing wheel 420 and the outlet 438 that is directedtoward the polishing wheel 424. In operation, a polishing medium, in theform of a slurry, is pumped (pump not shown) into the tank 414 with acontrolled flow rate of, for example, 60 ml per minute via the slurrydispenser 412. The pump is typically capable of providing a flow rate ofbetween 17 ml to 17 liters per minute. The polishing medium issubsequently dispensed onto the polishing wheel 420 and the polishingwheel 424 via the outlet 436 and the outlet 438, respectively. Thepolishing medium is, for example, a slurry formed of one part aluminumoxide powder mixed with fifteen parts water. The particle size of thealuminum oxide powder is in the range of 1.0 to 0.05 microns dependingon the polishing station location, i.e., the polishing station 114 a,114 b, or 114 c. Finally, an outlet 440 disposed in the bottom of thetank 414 provides an outlet for recirculating the polishing medium.

[0056]FIG. 5 illustrates a side view of the pressure assembly 432 thatis a pressure device suitable for use within the polishing station 114illustrated in FIGS. 4A, 4B and 4C. The pressure assembly 432 includes astainless steel plate 510 whose ends, when installed, is connected toopposing walls of, for example, the tank 414 of the polishing station114. The thickness of the plate 510 is such that negligible deflectionof the plate 510 occurs when the pressure assembly 432 is under load.The plate 510 has a first clearance hole 512 and a second clearance hole514 through which passes a first screw 516 and a second screw 518,respectively. The diameter of the clearance hole 512 and the clearancehole 514 is sufficiently large to allow the screw 516 and the screw 518to freely float as they pass through the plate 510. The screw 516 andthe screw 518 are conventional screws, such as a 2 inch 10-32 screw,that provide mechanical coupling to a block 520 by threading through afirst block surface 522 of the block 520, which is the surface of theblock 520 that is oriented toward the plate 510. A second block surface524 of the block 520 is oriented toward the substrate tape 124 uponwhich it contacts when installed. The block 520 is formed of a lowfriction material, such as Teflon, that is not damaging to thenon-polished surface 126 of the substrate tape 124. The dimensions ofthe block 520 are, for example, 2 inches wide by 2.75 inches long by 1inch thick. Fitting flush against the head of the screw 516 is astandard washer 526. Furthermore, a spring 528 is arranged between thewasher 526 and the plate 510. Similarly, fitting flush against the headof the screw 518 is a standard washer 530 and a spring 532 is arrangedbetween the washer 530 and the plate 510. The spring 528 and the spring532 are conventional springs having a maximum spring force of, forexample, 2205 lbs and that have a large enough inside diameter to allowthe screw 516 and the screw 518 to pass. Lastly, a control screw 534 isdisposed between the screw 516 and the screw 518 and threaded entirelythrough the plate 510. Having passed through the plate 510 the threadedend 6 f the control screw 534 subsequently passes through a spring 536disposed between the plate 510 and the block surface 522 of the block520 and then comes into contact with the block surface 522 of the block520, as shown in FIG. 5. The control screw 534 is conventional machinescrew, such as a {fraction (3/8)} inch 6-32 screw that is 1.5 incheslong. The spring 536 is a conventional spring having a maximum springforce of, for example, 2205 lbs and has a large enough inside diameterto allow the control screw 534 to pass.

[0057] With continuing reference to FIG. 5, the block 520 is essentiallysuspended from the plate 510 via the screw 516 and the screw 518 thatare allowed to freely float as they pass through the plate 510. Thespring 528 and the spring 532 provide upward force against the washer526 and the washer 530, respectively, thereby creating a pulling actionto draw the block 520 toward the plate 510, where the plate 510 providesa stationary mechanical reference within the tank 414 of the polishingstation 114. In its relaxed state (i.e., the control screw 534 in aretracted position) the spring 536 prevents the block surface 522 of theblock 520 from coming into contact with the plate 510. However, when thecontrol screw 534 is adjusted such that its threaded end is in contactwith the block surface 522 of the block 520 it provides an opposingforce to the spring 528 and the spring 532, thereby forcing the block520 to be pushed away from the plate 510 and into contact with thenon-polished surface 126 of the substrate tape 124. The pressureassembly 432 is capable of a maximum pressure of 1000 lbs per squareinch but is typically set within a range of 0 to 300 lbs per squareinch. A load sensor (not shown) is disposed within the center of theblock 520 and is connected through a cable (not shown) to an externalreadout display so that the pressure exerted by the pressure assembly432 upon the substrate tape 124 may be monitored. The load sensor is,for example, a simple button sensor, such as Sensotec Model 53 AL131.

[0058]FIGS. 6A and 6B illustrate a side view and an end view,respectively, of the rinsing station 116 that is a substrate tapecleaning mechanism suitable for use within the polishing system 100 ofthe present invention.

[0059] The rinsing station 116 includes multiple instantiations of asprayer assembly 610, for example a sprayer assembly 610 a and a sprayerassembly 610 b, disposed within a tank 612 formed of stainless steel.The tank 612 has an entry slot 614 and an exit slot 616 through whichthe substrate tape 124 may translate. Inserted in the entry slot 614 andthe exit slot 616 is a squeegee (not shown) formed of felt for removingexcess water from the substrate tape 124 as it passes therethrough.

[0060] Each sprayer assembly 610 includes an inlet 618 feeding aconventional spray nozzle 620. More specifically, the sprayer assembly610 a includes an inlet 618 a feeding a spray nozzle 620 a and thesprayer assembly 610 b includes an inlet 618 b feeding a spray nozzle620 b. The inlet 618 a and the inlet 618 b pass through the wall of thetank 612 and are connected to a source of rinsing water, such as tapwater or de-ionized water, having a pressure that is typically less than75 psi. The sprayer assembly 610 a and the sprayer assembly 610 b areoriented 180 degrees to one another within the tank 612 such that thespray nozzle 620 a and the spray nozzle 620 b are facing one another andare sufficiently spaced to allow the substrate tape 124 to pass between,as shown in FIG. 6B. In operation, the rinsing water is released intothe tank 612 via the sprayer assembly 610 a and the sprayer assembly 610b and directed onto the substrate tape 124 for the purpose of rinsingthe polishing medium residue from the surfaces of the substrate tape124. Finally, an outlet 622 disposed in the bottom of the tank 612provides a drain for expelling the rinsing water.

[0061]FIG. 7 illustrates a top view of the polishing station 118 that isa mechanical polisher suitable for use within the polishing system 100of the present invention.

[0062] The polishing station 118 includes multiple instantiations of thepolisher assembly 410 as described in FIG. 4. For example, the polishingstation 118 includes a polisher assembly 410 a having a polishing wheel420 a and a polishing wheel 424 a driven by a motor 428 a, a polisherassembly 410 b having a polishing wheel 420 b and a polishing wheel 424b driven by a motor 428 b, and a polisher assembly 410 c having apolishing wheel 420 c and a polishing wheel 424 c driven by a motor 428c. For simplicity of illustration, the pressure assembly 432 associatedwith each polishing wheel is not shown in FIG. 7.

[0063]FIG. 7 illustrates but one example driving mechanism, thoseskilled in the art will appreciate that the multiple polishing wheelsmay be rotatably driven by other conventional means, for example, by asingle motor 428 with multiple belts.

[0064] The polisher assembly 410 a, the polisher assembly 410 b, and thepolisher assembly 410 c are disposed within a tank 710 formed ofstainless steel. The tank 710 has an entry slot 712 and an exit slot 714through which the substrate tape 124 may translate. Inserted in theentry slot 712 and the exit slot 714 is a squeegee (not shown) formed ofsilicon rubber and felt for removing excess slurry from the substratetape 124 as it passes therethrough.

[0065] When installed, the polishing wheel 420 a and the polishing wheel424 a of the polisher assembly 410 a, the polishing wheel 420 b and thepolishing wheel 424 b of the polisher assembly 410 b, the polishingwheel 420 c and the polishing wheel 424 c of the polisher assembly 410c, are all aligned along the axis of the substrate tape 124 passingthrough the tank 710. Additionally, all polishing wheels are aligned ona horizontal plane such that they make contact with the polished surface128 of the substrate tape 124.

[0066] The polishing station 118 further includes multipleinstantiations of the slurry dispenser 412 for directing the polishingmedium onto the polishing wheels as described in FIG. 4. However, forsimplicity of illustration, the multiple instantiations of the slurrydispenser 412 are not shown in FIG. 7. Likewise, it can be assumed thatthe tank 710 has on or more outlets for recirculating the polishingmedium as described in FIG. 4. Again, for simplicity of illustration,the outlets are not shown in FIG. 7.

[0067]FIGS. 8A and 8B illustrate a side view and a top view,respectively, of the rinsing station 120 that is a substrate tapecleaning mechanism suitable for use within the polishing system 100 ofthe present invention.

[0068] The rinsing station 120 includes a tank 810 formed of stainlesssteel and having an entry slot 812 and an exit slot 814 through whichthe substrate tape 124 may translate. Inserted in the entry slot 812 andthe exit slot 814 is a squeegee (not shown) formed of silicon rubber andfelt for removing excess water from the substrate tape 124 as it passestherethrough. Disposed within tank 810 is a polisher assembly 816 incombination with multiple instantiations of a sprayer assembly 830 thatis identical to the sprayer assembly 610 having an inlet and a spraynozzle as described in FIGS. 6A and 6B. For example, the rinsing station120 includes a sprayer assembly 830 a, a sprayer assembly 830 b, asprayer assembly 830 c, and a sprayer assembly 830 d.

[0069] The polisher assembly 816 includes a polishing wheel 818 mountedon a rotatable shaft 820 whose ends pass through opposing walls of thetank 810 leaving the polishing wheel 818 suspended within the tank 810.Similarly, the polisher assembly 816 includes a polishing wheel 822mounted on a rotatable shaft 824 whose ends pass through opposing wallsof the tank 810 leaving the polishing wheel 824 suspended within thetank 810. When installed, the polishing wheel 818 and the polishingwheel 822 of the polisher assembly 816 are aligned along the axis of thesubstrate tape 124 passing through the tank 810. However, the polishingwheel 818 and the polishing wheel 822 of the polisher assembly 816 arenot arranged on the same horizontal plane within the tank 810. Instead,the polishing wheel 818 and the polishing wheel 822 are arranged onopposing sides of the substrate tape 124. More specifically, thepolishing wheel 818 makes contact when installed with the non-polishedsurface 126 of the substrate tape 124 and the polishing wheel 822 makescontact when installed with the polished surface 128 of the substratetape 124, as shown in FIG. 8A.

[0070] The polishing wheel 818 and the polishing wheel 822 are softpolishing wheels, such as a Boston Felt soft wheel with a “Shore Ahardness” in the range of 30 to 40. A conventional motor 826 rotatablydrives the shaft 820 and subsequently the polishing wheel 818. The motor826 additionally drives the shaft 824 and subsequently the polishingwheel 822 via a belt 828 that couples the rotational motion of the shaft820 to the shaft 824 via pulleys (not shown). The motor 826 is, forexample, a conventional 0.5 hp motor, such as Dayton 5K984D motor, thatis capable of a rotational speed of up to 1600 rpm. FIG. 8B illustratesbut one example driving mechanism, those skilled in the art willappreciate that the shaft 820 to the shaft 824 may be rotatably drivenby other conventional means.

[0071] Unlike the polisher assembly 410 described in FIGS. 4A, 4B and4C, the polisher assembly 816 does not include any instantiations of thepressure assembly 432 that is described in FIG. 5.

[0072] The inlet of each sprayer assembly 830 passes through the wall ofthe tank 810 and feeds its associated spray nozzle, where each inlet isconnected to a source of rinsing water, such as tap water or de-ionizedwater, having a pressure that is typically less than 75 psi. The sprayerassembly 830 a and the sprayer assembly 830 b are oriented 180 degreesto one another within the tank 810 such that their spray nozzles arefacing one another and are sufficiently spaced to allow the substratetape 124 to pass between, as shown in FIG. 8A. The sprayer assembly 830c is oriented at an angle directing its spray nozzle toward the contactpoint of the polishing wheel 818 and the non-polished surface 126 of thesubstrate tape 124. Likewise, the sprayer assembly 830 d is oriented atan angle directing its spray nozzle toward the contact point of thepolishing wheel 822 and the polished surface 128 of the substrate tape124, as shown in FIG. 8A.

[0073] In operation, the rinsing water is released into the tank 810 viathe sprayer assembly 830 a, the sprayer assembly 830 b, the sprayerassembly 830 c, and the sprayer assembly 830 d and directed onto thesubstrate tape 124 for the purpose of rinsing the polishing mediumresidue from the surfaces of the substrate tape 124. Finally, an outlet832 and an outlet 834 disposed in the bottom of the tank 810 provide adrain for expelling the rinsing water.

[0074] In operation, and with reference to FIG. 1, the polishing wheelsin the polishing station 114 a, the polishing station 114 b, thepolishing station 114 c, the polishing station 118, and the rinsingstation 120, are selected having a hardness according to Table 1 belowand installed. Additionally, the particle size of the polishing mediumwithin the slurry feeding the polishing station 114 a, the polishingstation 114 b, the polishing station 114 c, and the polishing station118 is selected according to Table 1 below. TABLE 1 Polishing wheelhardness and polishing medium particle size as required for thepolishing system 100 Polishing wheel Polishing medium Shore A hardnessparticle size Acceptable Specific Acceptable Specific range examplerange example Polishing Above 85 Diamond 0.3 to 1.0 1.0 station 114aHard microns microns Polishing 55 to 65 Hard 0.05 to 0.3 0.3 station114b microns microns Polishing 55 to 65 Hard 0.05 to 0.3 0.3 station114c microns microns Polishing 55 to 65 Hard ≦0.05 0.05 station 118microns microns Rinsing 30 to 40 Soft n/a n/a station 120

[0075] With continuing reference to FIGS. 1 through 8B, the operation ofthe polishing system 100 is described as follows. The reel 210 of thespool 110 a that has a length of substrate tape 124 wound upon it ismounted at the front end of the polishing system 100. The leader of thesubstrate tape 124 is laced through the tape feeder 112 between the belt312 and the belt 320 (FIGS. 3A, 3B and 3C), all the while the substratetape 124 is riding on the guide wheel 130. The leader of the substratetape 124 is then laced through the polishing station 114 a via its entryslot 416 and subsequently through its polisher assembly 410 and finallythrough its exit slot 418. The leader of the substrate tape 124 is thenlaced through the rinsing station 116 a via its entry slot 614 andsubsequently passing in close proximity to multiple instantiations ofthe of the sprayer assembly 610 and finally through its exit slot 616.The leader of the substrate tape 124 is then laced through the polishingstation 114 b via its entry slot 416 and subsequently through itspolisher assembly 410 and finally through its exit slot 418. The leaderof the substrate tape 124 is then laced through the rinsing station 116b via its entry slot 614 and subsequently passing in close proximity tomultiple instantiations of the of the sprayer assembly 610 and finallythrough its exit slot 616. The leader of the substrate tape 124 is thenlaced through the polishing station 114 c via its entry slot 416 andsubsequently through its polisher assembly 410 and finally through itsexit slot 418. The leader of the substrate tape 124 is then lacedthrough the rinsing station 116 c via its entry slot 614 andsubsequently passing in close proximity to multiple instantiations ofthe of the sprayer assembly 610 and finally through its exit slot 616.The leader of the substrate tape 124 is then laced through the polishingstation 118 via its entry slot 712 and subsequently through its multipleinstantiations of the polisher assembly 410 and finally through its exitslot 714. The leader of the substrate tape 124 is then laced through therinsing station 120 via its entry slot 812 and subsequently passing inclose proximity to multiple instantiations of the of the sprayerassembly 830 and through its polisher assembly 816 and finally throughits exit slot 814. Lastly, the leader of the substrate tape 124 is lacedonto the spool 110 b, all the while the substrate tape 124 is riding onthe guide wheel 132 and the tension of the substrate tape 124 is set byadjusting the torque on the motor 212 of the spool 110 a and on themotor 212 of the spool 110 b. The tension is set to a level sufficientto maintain the flatness of the substrate tape 124 for polishing, yetwithout stressing the substrate tape 124 to its breaking point.

[0076] Having laced the substrate tape 124 through all the elements ofthe polishing station 100, the water source feeding the rinsing station116 a, the rinsing station 116 b, the rinsing station 116 c, and therinsing station 120 is activated. Additionally, the slurry pumps (notshown) feeding the slurry dispenser 412 of the polishing station 114 a,the slurry dispenser 412 of the polishing station 114 b, and the slurrydispenser 412 of the polishing station 114 c are activated and all flowrates are adjusted via the pump controls. Likewise, the slurry pumpfeeding the multiple instantiations of the slurry dispenser 412 of thepolishing station 118 is activated and the flow rate is adjusted via thepump control. In all cases, the flow rate is set such that an optimalsupply of polishing medium is present at the polishing wheels to achievethe desired result.

[0077] Having begun the flow of rinsing water and polishing medium, allmotors within the polishing system 100 are activated. More specifically,the motor 428 of the polishing station 114 a is activated, the motor 428of the polishing station 114 b is activated, the motor 428 of thepolishing station 114 c is activated, and the multiple instantiations ofthe motor 428 of the polishing station 118 are activated. Additionally,the motor 212 of the spool 110 a and the motor 212 of the spool 110 bare activated. Lastly, the motor 328 of the tape feeder 112 isactivated. The pressure exerted on the substrate tape 124 by the belt312 and the belt 320 of the tape feeder 112 creates sufficient frictionto cause the substrate tape 124 to translate through the polishingsystem 100 due to the rotation of the belts 312 and 320 of the tapefeeder 112. The translation speed of the substrate tape 124 is set byadjusting the speed of the tape feeder 112 to provide a controlled rateof translation to allow the proper exposure time of the substrate tape124 to the various polishing and cleaning events. The translation ratecan vary in a range of from about 0.1 to about 1.5 cm/min; preferablyform about 0.15 to about 0.5 cm/min. A typical translation rate is, forexample, 0.2 to about 0.4 cm/min.

[0078] Subsequently, the pressure of the substrate tape 124 against thepolishing wheels disposed throughout the polishing system 100 is set byadjusting the control screw 534 of each instantiation of the pressureassembly 432 within the polishing station 114 a, by adjusting thecontrol screw 534 of each instantiation of the pressure assembly 432within the polishing station 114 b, by adjusting the control screw 534of each instantiation of the pressure assembly 432 within the polishingstation 114 c, and by adjusting the control screw 534 of eachinstantiation of the pressure assembly 432 within the polishing station118. In all cases, the pressure is set within a range of 0 to 300 lbsper square inch by monitored the pressure via the load sensor that isbuilt into each block 520.

[0079] Subsequently, the roughness monitor 122 is activated and itsposition is manually adjusted via the 3-axis adjustable stage such thatthe distance between the substrate tape 124 and the roughness monitor122 is appropriate for measuring roughness to the required accuracy.Having begun the flow of rinsing water and polishing medium, and havingactivated all motors, the substrate tape 124 is now translating throughthe polishing system 100 and experiencing multiple polishing and rinsingevents in succession. More specifically, the substrate tape 124experiences the first polishing and rinsing event via the polishingstation 114 a and the rinsing station 116 a. The polishing wheelhardness and polishing medium particle size is as shown in Table 1, andthus this first polishing event is considered the most aggressivepolishing event within the polishing system 100.

[0080] Next, the substrate tape 124 experiences a series or moremoderate polishing events and subsequent rinsing events by passingthrough the polishing station 114 b and the rinsing station 116 b, thenthrough the polishing station 114 c and the rinsing station 116 c, andthen through the polishing station 118. The polishing wheel hardness andpolishing medium particle size for the polishing station 114 b, thepolishing station 114 c, and the polishing station 118 is as shown inTable 1, and thus these polishing events are considered less aggressivethan that of the polishing station 114 a.

[0081] Lastly, the substrate tape 124 experiences a final polishing andrinsing event via the rinsing station 120 that provides the function ofboth rinsing and polishing, but without the presence of a polishingmedium. The polishing wheel hardness is as shown in Table 1, and thusthis polishing event is considered the least aggressive polishing eventwithin the polishing system 100 and applies the most fine and smoothsurface quality to the polished surface 128 of the substrate tape 124.

[0082] In this way, the substrate tape 124 experiences, via progressivestages, first a rough, then a medium, then a fine polishing event incombination with a respective rinsing event as it translates through thepolishing system 100, thereby achieving in a single pass through thepolishing system 100 a surface smoothness that is suitable for thesubsequent deposition of a buffer layer.

[0083] It is noted that the polishing wheel hardness and polishingmedium particle size is not limited to that as shown in Table 1, othercombinations are possible depending on the product application.

[0084]FIG. 9 illustrates a method 900 in accordance with the inventionof operating the polishing system 100 that is a mechanical polishingsystem suitable for polishing long lengths of metal substrate tape usedin the manufacture of HTS-coated tape. The method 900 includes the stepsof:

[0085] Step 910: Mounting payout spool

[0086] In this step, the user mounts the reel 210 of the spool 110 awithin the polishing system 100. The reel 210 has a length of substratetape 124 wound upon it. Method 900 proceeds to step 912.

[0087] Step 912: Lacing Substrate Tape Through Tape Feeder

[0088] In this step, the user laces the leader of the substrate tape 124through the tape feeder 112 between the belt 312 and the belt 320 of thetape feeder 112 (FIGS. 3A, 3B and 3C), all the while the substrate tape124 is riding on the guide wheel 130. Method 900 proceeds to step 914.

[0089] Step 914: Lacing substrate tape through polishing and rinsingstations In this step, the user laces the leader of the substrate tape124 through the polishing station 114 a via its entry slot 416 andsubsequently through its polisher assembly 410 and finally through itsexit slot 418. The user then laces the leader of the substrate tape 124through the rinsing station 116 a via its entry slot 614 andsubsequently passing in close proximity to multiple instantiations ofthe of the sprayer assembly 610 and finally through its exit slot 616.The user then laces the leader of the substrate tape 124 through thepolishing station 114 b via its entry slot 416 and subsequently throughits polisher assembly 410 and finally through its exit slot 418. Theuser then laces the leader of the substrate tape 124 through the rinsingstation 116 b via its entry slot 614 and subsequently passing in closeproximity to multiple instantiations of the of the sprayer assembly 610and finally through its exit slot 616. The user then laces the leader ofthe substrate tape 124 through the polishing station 114 c via its entryslot 416 and subsequently through its polisher assembly 410 and finallythrough its exit slot 418. The user then laces the leader of thesubstrate tape 124 through the rinsing station 116 c via its entry slot614 and subsequently passing in close proximity to multipleinstantiations of the of the sprayer assembly 610 and finally throughits exit slot 616. The user then laces the leader of the substrate tape124 through the polishing station 118 via its entry slot 712 andsubsequently through its multiple instantiations of the polisherassembly 410 and finally through its exit slot 714. The user then lacesthe leader of the substrate tape 124 through the rinsing station 120 viaits entry slot 812 and subsequently passing in close proximity tomultiple instantiations of the of the sprayer assembly 830 and throughits polisher assembly 816 and finally through its exit slot 814. Method900 proceeds to step 916.

[0090] Step 916: Lacing Substrate Tape Onto Take-Up Spool

[0091] In this step, the user laces the leader of the substrate tape 124onto the spool 110 b, all the while the substrate tape 124 is riding onthe guide wheel 132. Method 900 proceeds to step 918.

[0092] Step 918: Setting Substrate Tape Tension

[0093] In this step, the user sets the tension of the substrate tape 124by adjusting the torque on the payout spool and take-up spool motors.More specifically, by adjusting the torque on the motor 212 of the spool110 a and on the motor 212 of the spool 10 b. The tension is set to alevel sufficient to maintain the flatness of the substrate tape 124 forpolishing, yet without stressing the substrate tape 124 to its breakingpoint. Method 900 proceeds to step 920.

[0094] Step 920: Pumping Water into Rinsing Stations

[0095] In this step, the user activates the water source feeding therinsing station 116 a, the rinsing station 116 b, the rinsing station116 c, and the rinsing station 120. Method 900 proceeds to step 922.

[0096] Step 922: Activating Slurry Pumps and Adjusting Flow Rate

[0097] In this step, the user activates the slurry pump feeding theslurry dispenser 412 of the polishing station 114 a and adjusts the flowrate via the pump controls. Subsequently, the user activates the slurrypump feeding the slurry dispenser 412 of the polishing station 114 b andadjusts the flow rate via the pump controls. Subsequently, the useractivates the slurry pump feeding the slurry dispenser 412 of thepolishing station 114 c and adjusts the flow rate via the pump controls.Subsequently, the user activates the slurry pump feeding the multipleinstantiations of the slurry dispenser 412 of the polishing station 118and adjusts the flow rate via the pump controls. In all cases, the flowrate is set such that an optimal supply of polishing medium is presentat the polishing wheels to achieve the desired result. Method 900proceeds to step 924.

[0098] Step 924: Activating Polishing System

[0099] In this step, the user activates the motor 428 of the polishingstation 114 a, the motor 428 of the polishing station 114 b, the motor428 of the polishing station 114 c, and the multiple instantiations ofthe motor 428 of the polishing station 118. Additionally, the useractivates the motor 212 of the spool 110 a and the motor 212 of thespool 110 b. Lastly, the user activates the motor 328 of the tape feeder112. Method 900 proceeds to step 926.

[0100] Step 926: Setting Substrate Tape Translation Speed

[0101] In this step, the user sets the translation speed of thesubstrate tape 124 by adjusting the speed of the tape feeder 112 toprovide a controlled rate of translation to allow the proper exposuretime of the substrate tape 124 to the polishing and cleaning events. Atypical translation rate is, for example, 1.0 inch per 7 minutes. Method900 proceeds to step 928.

[0102] Step 928: Adjusting Substrate Tape Pressure Devices

[0103] In this step, the user adjusts the pressure of the substrate tape124 against the polishing wheels by adjusting the control screw 534 ofeach instantiation of the pressure assembly 432 within the polishingstation 114 a, by adjusting the control screw 534 of each instantiationof the pressure assembly 432 within the polishing station 114 b, byadjusting the control screw 534 of each instantiation of the pressureassembly 432 within the polishing station 114 c, and by adjusting thecontrol screw 534 of each instantiation of the pressure assembly 432within the polishing station 118. In all cases, the pressure is setwithin a range of 0 to 300 lbs per square inch by monitoring thepressure via the load sensor that is built into the block 520. A cableconnected to the sensor provides readout to an external display to allowmonitoring by the user. Method 900 proceeds to step 930.

[0104] Step 930: Activating Roughness Monitor

[0105] In this step, the user activates the roughness monitor 122.Method 900 proceeds to step 932.

[0106] Step 932: Adjusting Roughness Monitor

[0107] In this step, the user manually adjusts the position of theroughness monitor 122 via the 3-axis adjustable stage. Morespecifically, the roughness monitor 122 is adjusted such that thedistance between the substrate tape 124 and the roughness monitor 122is, for example, 1 inch. Method 900 proceeds to step 934.

[0108] Step 934: Deactivating Polishing System Upon Completion

[0109] In this step, when the entire length of the substrate tape 124has been exposed to the polishing system 100, the user deactivates allmotors, pumps, and water supplies within the polishing system 100 andremoves the take-up spool. More specifically, the user removes the reel210 of the spool 110 b that has the full length of the substrate tape124 wound upon it. Method 900 ends.

1. A process for the continuous single pass multistage surface polishingof a metal tape comprising a] providing an unpolished metal tape b]providing a polishing chamber comprising a multiplicity of surfacetreatment units, each unit comprising a polishing station and a rinsingstation c] continuously feeding the unpolished metal tape into thepolishing chamber d] sequentially passing the metal tape through aseries of surface treatment units where each successive surfacetreatment unit further polishes a surface of the tape; and e] retrievingpolished metal tape from the chamber.
 2. The process of claim 1 wherethe tape is provided to the chamber from a feed reel and is retrievedfrom the chamber by a take-up reel and where the reels are synchronizedto maintain a selected tension in the tape as it moves through thepolishing chamber
 3. The process of claim 1 where the tape is whereinthe tape is selected from the group consisting of stainless steel,nickel, and nickel alloy tapes.
 4. The process of claim 1 where the tapeis moves through the deposition chamber at a rate in the range of fromabout 0.2 to about 0.4 cm/min.
 5. The process of claim 1 where the tapeis moves through the deposition chamber at a rate in the range of fromabout 0.15 to about 0.5 cm/min.
 6. The process of claim 1 where the tapeis moves through the deposition chamber at a rate in the range of fromabout 0.1 to about 1.5 cm/min.
 7. The process of claim 1 where theabrasive material used to surface treat the tape is a water slurry ofaluminum oxide.
 8. The process of claim 1 where the ratio of abrasivematerial to water in the slurry is in the range of from about 1:10 toabout 1:20.
 9. The process of claim 1 where the ratio of abrasivematerial to water in the slurry is in the range of from about 1:14 toabout 1:16.
 10. The process of claim 1 where the flow rate of abrasiveslurry in the polishing steps is from about 0.017 l/min to about 17l/min.
 11. The process of claim 1 where the flow rate of abrasive slurryin the polishing steps is from about 0.05 l/min to about 5 l/min. 12.The process of claim 1 where the flow rate of abrasive slurry in thepolishing steps is from about 0.1 l/min to about 1 l/min.
 13. Theprocess of claim 1 where the abrasive material in the initial polishingstep has a Shore A hardness of above 85 and a particle size in the rangeof from about 0.3 microns to about 1.0 micron.
 14. The process of claim1 where the abrasive material in the second polishing step has a Shore Ahardness of from about 55 to about 65 and a particle size in the rangeof from about 0.05 microns to about 0.3 microns.
 15. The process ofclaim 1 where the abrasive material in the final polishing step has aShore A hardness of from about 55 to about 65 and a particle size of nomore than about 0.05 microns.
 16. A reel-to-reel single-pass continuousmechanical polishing system suitable for polishing long lengths of metalsubstrate tape used in the manufacture of HTS-coated tape comprisingmultiple instantiations of a polishing station in combination with asubsequent rinsing station arranged along the axis of the metalsubstrate tape that is continuously translating between a payout spooland a take-up spool whereby the metal substrate tape experiences aseries of polishing and cleaning events to progressively diminish itssurface roughness and achieve a surface smoothness that is acceptablefor depositing a buffer layer in the manufacture of HTS-coated tape.